How to Stop the Spread of Gyrodactylus Salaris

G. salaris is a tiny creature measuring less than half a millimetre in length. It uses its tiny claws to attach itself to the skin ofyoung salmon, which it then eats. G. salaris breeds prolifically and a young salmon may be host to up to 10,000 individual specimensbefore it dies. The parasite is often referred to as the salmon killer or simply, Gyro.

Why Should this Concern Me?

The effects of this illness are so serious for the salmon
that it can disappear completely from the infected rivers .
If we dont do something, fishing for wild salmon in
Norway could be consigned to the history books. For this
reason it is very important that everyone who is out and
about around rivers and fresh water knows what to do.
We all have to do our bit to ensure that this parasite does
not spread to other rivers.

Where does G. Salaris Come from?

It is believed that G. salaris is widespread in rivers which
flow into the Baltic Sea from Finland and Russia and possibly
also Eastern Sweden. It seems that the Baltic salmon
can withstand the parasite better than our own. In
Norway, the parasite was first discovered in 1975 after
grower stock was imported from Sweden. This underlines
how careful we must be in moving and setting out fish.

Can Salmon Become Resistant?

The Norwegian salmon has very little resistance to the
parasite. It is uncertain how long it will take to develop
resistance which is high enough that the parasite does not
threaten our salmon stocks. Experience from Norwegian
watercourses which are infected by Gyro is that the
parasite leads to almost total extinction of salmon.

How does the Parasite Spread?

The parasite can be spread by fish, tackle, nets and water
from infected watercourses and water systems. In most
spreading where the parasite has been introduced into new
parts of Norway this has been the result of infected fish
being moved and then released, but it can also be spread
through tackle which is used on several watercourses.
G. salaris can survive for several days in damp
surroundings, for example in plastic bags, on dead fish,
in other packaging and equipment, such as waders, nets,
lines and landing nets. It is not just fishing tackle which
can cause infection, but everything we use in and near
fresh water: rubber dinghies, lilos, canoes and kayaks.
It isnt difficult to get rid of G. salaris, provided the
correct procedure is followed.

Do Not:

Release live fish into the wild unless you have cleared
this with the District Governor

Wash and gut fish anywhere other than where you
caught them.

Take tackle from one watercourse to another without
disinfecting it.

Throw water out into another watercourse than the
one it was fetched from.